On the infrasound detected from the 2013 and 2016 DPRK's underground nuclear tests

Abstract

The underground nuclear tests by the Democratic People's Republic of Korea (DPRK) generated atmospheric infrasound both in 2013 and 2016. Clear detections were made in the Russian Federation (I45RU) and Japan (I30JP) in 2013 at stations from the International Monitoring System. Both tropospheric and stratospheric refractions arrived at the stations. In 2016, only a weak return was potentially observed at I45RU. Data analysis and propagation modeling show that the noise level at the stations and the stratospheric circumpolar vortex were different in 2016 compared to 2013. As the seismic magnitude of the 2013 and 2016 nuclear test explosions was comparable, we hypothesize that the 2016 test occurred at least 1.5 times deeper. In such a case, less seismic energy would couple through the lithosphere‐atmosphere interface, leading to less observable infrasound. Since explosion depth is difficult to estimate from seismic data alone, this motivates a synergy between seismics and infrasonics.

Yield Estimates for the Six North Korean Nuclear Tests From TeleseismicPWave Modeling and Intercorrelation ofPandPnRecordings

“…A variety of methods have been used to estimate the yields or seismic moments of the six tests, including assumed transportability of body wave, surface wave, or Lg magnitude yield scaling relations (e.g., Chun et al, ; Hartmann et al, ; Yao et al, ; Zhang & Wen, ; Zhao et al, , , , , Zhao, Xie, Wang, et al, ,Zhao, Xie, He, et al, ); modeling of surface deformation (Wang et al, ; Wei, ), regional waveforms and spectra (e.g., Murphy et al, ; Rougier et al, ; Stevens & O'Brien, ; Stroujkova, ; Wang et al, ), regional coda envelopes (e.g., Pasyanos & Myers, ), network‐averaged teleseismic P wave spectra (e.g., Murphy et al, ), and teleseismic P waveforms (e.g., Chaves et al, ; Ni et al, ); and moment tensor inversion for the total and isotropic moment of the explosions (e.g., Alvizuri & Tape, ; Barth, ; Cesca et al, ; Chiang et al, ; Ford et al, ; Ichinose et al, ; Liu, Li, Zahradnik, Sokos, Liu, et al, ,Liu, Li, Zahradník, Sokos, & Plicka, ; Vavrycuk & Kim, ; Wang et al, ; Yao et al, ). Some depth constraints are inferred from infrasound as well (Assink et al, ). We summarize the ranges of yield estimates from the literature in Table , with details provided in Table S1.…”

Seismoacoustic Coupled Signals From Earthquakes in Central Italy: Epicentral and Secondary Sources of Infrasound

“…Understanding seismoacoustical coupling is of interest for the verification of the CTBT, where large underground explosions generate infrasound, which can be detected over long ranges (Assink et al, ). The fusion of seismic and infrasound data from underground sources will lead to better source characterization in terms of, for example, source depth and yield.…”

“…Understanding seismic‐to‐infrasonic coupling is important for characterizing sources in the subsurface. Assink et al () have used infrasound detections of the 2013 and 2016 underground nuclear tests by the Democratic People's Republic of Korea in order to further constrain source depth, which is difficult to estimate from seismic data alone. Whitaker and Mutschlecner () and Mutschlecner and Whitaker () have investigated infrasound signals from explosions and earthquakes and formulated signal amplitude and duration versus yield or magnitude relations.…”

Responses to comments by reviewer #1

“…Especially longperiod waveforms with periods above 10 s recorded at regional distances show a high waveform similarity and a substantially increased amplitude, revealing a very similar radiation pattern of all events and a larger moment release for the 2017 nuclear test. In recent years, MTIs have been performed for nuclear tests in North Korea, including those carried out in , 2013(Ford et al, 2010Barth, 2014;Vavrycuk and Kim, 2014;Hartmann et al, 2017). All MTIs were performed by fitting low-frequency full waveform seismic data at regional distances, either in the time or in the frequency domain.…”